To assist in navigation, pilots are typically in contact with a facility responsible for aircraft within a defined area, such as an Air Route Traffic Control Center (ARTCC). Pilots use communications with a particular ARTCC to receive traffic information of other aircraft in their proximity to maintain proper spacing. Pilots often use this information to determine specific traffic conditions they may face or to formulate possible actions if the need arises. The ARTCC may also send other information such as emergency alerts or safety alerts. For example, the ARTCC may send to the pilot an alert that the aircraft is flying at an unsafe altitude relative to the aircraft's current position, heading or speed. The ARTCC may also send instructions to avoid possible safety issues or to correct safety issues the pilot may be experiencing. Additionally, the ARTCC may send vectors for navigational assistance or to help maintain separation of aircraft.
When moving between areas assigned to different ARTCCs, air traffic control (ATC) may instruct the pilot to switch frequencies to communication with another ATC, called a “handoff.” During the handoff, the pilot will manually switch the communication system from the current communication frequency to the new communication frequency. When transmitting and receiving at the new communication frequency, the pilot will typically check in with the new ATC on the new communication frequency by providing the aircraft information and altitude. The ATC on the new communication frequency acknowledges the pilot, letting the pilot know that the ATC has audio communication with the aircraft.
Because of the distance between ATCs in some flight paths, a system of remote communication outlets (RCOs) may be implemented. An RCO is an unmanned VHF/UHF transmitter/receiver radio relay facility that expands the ARTCC air/ground communications coverage. The RCO will relay a call from a pilot to an ATC, or the reverse, so that it appears to the pilot that the pilot is in direct communication with the ATC. Typically, pilots find RCO frequencies in charts or publications such as the Airport/Facility Directory. Each RCO typically transmits and receives on a specific communication frequency, and some have more than one communication frequency. The maps provided in these types of publications are usually general in nature and do not provide specific details regarding the terrain. For example, in some situations there is no information regarding communication sectorization.
In use, a pilot may transfer communications between ATCs and RCOs via a series of handoffs as previously described. In some instances, the handoff may not be accomplished if the RCO is not within range of the aircraft radio, the RCO is not operational, or the RCO communication frequency is not being monitored. In some situations, the pilot may miss the handoff altogether. If the pilot senses that a handoff did not occur, the pilot may rotate through available frequencies. In some examples, the pilot can communicate with other aircraft in the area if in communication with those aircraft and request a communication frequency that is being monitored. Sometimes, the handoff may have occurred correctly but the pilot may be under a false impression that it did not happen. For example, the distances between RCOs may be vast in some areas, and the ATC in that area may be monitoring a significant number of RCOs. In that instance, the pilot may be in communication with the ATC but not realize it because of the time it takes for the ATC to respond to the pilot's identification communication.
Conventionally, the pilot or flight crew selects the RCO and the RCO communication frequency, if the RCO uses more than one, based on the aircraft's proximate location to the RCO. The pilot typically locates the aircraft on a map, which has the various RCOs in the location of aircraft and their generalized transceiver ranges delineated. In many instances, the transceiver range may be illustrated as a radius around the RCO. As described above, the range circles are typically general in nature. For example, the ranges typically do not account for the height of the aircraft and local terrain conditions that may affect the transceiver range. As discussed above, if the RCO is not operational, is out of range, is blocked by the terrain, or is busy, acknowledgement of the attempted handoff may be delayed or may not happen at all.
It is with respect to these and other considerations that the disclosure made herein is presented.